Field of the Invention
The present invention relates to a solid-state imaging apparatus and a camera.
Description of the Related Art
A solid-state imaging apparatus includes a pixel array in which a plurality of pixels are arrayed, a plurality of processing units which process signals from respective pixels on each column of the pixel array, and an output line configured to output a signal from each processing unit.
Some solid-state imaging apparatuses have an arrangement in which a plurality of processing units are divided into a plurality of groups such that each of them includes two or more processing units, and one switch which connects the two or more processing units and an output line is provided for each group. For example, in a case that a signal is output from each processing unit of a certain group, the signals from two or more processing units of that group are sequentially output while setting the switch in a conductive state in that group, whereas the switch is set in a non-conductive state in each of the other groups. This arrangement is advantageous in increasing the operation speed of the solid-state imaging apparatus because the load capacitance of the output line is reduced as compared with a case in which all of the plurality of processing units are directly connected to the output line.
If a node between the switch and the two or more processing units of the above-described other group is set in a floating state while the switch is set in the non-conductive state in the other group, a potential variation may occur in this node. This may cause a malfunction of the solid-state imaging apparatus, latch-up, the insulation breakdown of a MOS transistor, or the like and reduce the reliability of the solid-state imaging apparatus.